A recent very significant advancement in the field of gas storage vessels, such as gas cylinders, is the high strength steel cylinder developed by Union Carbide Corporation and described and claimed in U.S. Pat. No. 4,461,657--Rana et al. and U.S. Pat. No. 4,578,113--Rana et al. This new gas storage cylinder enables the storage and transport of significantly more gas than is possible in a conventional cylinder of comparable size and weight because the gas can be safely maintained within the new gas storage cylinder at a pressure much higher than that possible with such conventional cylinders. For example, whereas a conventional cylinder may safely hold gas at a pressure up to about 2700 psia, the new high pressure gas storage cylinder may safely hold gas at a pressure up to about 4500 psia.
Gas is used at a use point at a defined pressure or pressure range. Generally this use pressure is less than the pressure of the gas source. In such cases a pressure regulator is employed to cause a reduction in the gas pressure and to ensure that the pressure of the gas going to the use point does not exceed the allowable use point pressure limit. Accordingly, many users of gases have regulators which can regulate the pressure of gas from about 2700 psia down to the desired use point pressure.
As previously discussed, the new gas storage cylinder provides gas at a pressure significantly in excess of the conventional pressures and thus at a pressure greater than that which can be handled by conventional regulators. One solution is to change the regulator to one which can handle the higher pressures. However, this solution is costly and may be time consuming if a user switches frequently from one gas source to another because the user may also have to be switching regulators.
It is thus desirable to have a regulator which can regulate high pressure gas, such as from the new high strength cylinder, for interfacing with existing pressure regulators designed to handle gas at lower pressure.
Once the new high strength gas storage cylinder is empty of gas it must be refilled. In order to retain the advantages of the high strength cylinder it must be recharged at the high pressure. Thus it is further desirable to have a high pressure regulator which will also allow refilling of the cylinder at high pressure.
Accordingly, it is an object of this invention to provide a regulator capable of rendering a high pressure gas source compatible with a lower pressure use point while also enabling recharging of the high pressure gas source to a high pressure.